IL-6 functions as an exocrine hormone in inflammation. Hepatocytes undergoing acute phase responses require exogenous IL-6
| Autor: | J Gauldie, W Northemann, G H Fey |
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| Rok vydání: | 1990 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 144:3804-3808 |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.144.10.3804 |
| Popis: | We have previously shown that IL-6 is the major monocyte- and fibroblast-derived regulator of acute phase protein gene expression and synthesis in hepatocytes in inflammation. Recently, we and others have shown that rat and human hepatoma cells express IL-6 mRNA, and the question arose as to whether normal hepatocytes express IL-6 and whether any such expression occurs under normal physiologic conditions or is seen in inflammation. Poly A+ mRNA of liver from normal rats and from rats undergoing an acute phase response was not positive when probed with cDNA for rat IL-6 under conditions in which macrophage mRNA was strongly positive. We then compared poly A+ mRNA from purified hepatocytes freshly isolated from normal rats--from rats that were undergoing an acute inflammatory response and from freshly isolated normal hepatocytes that had been cultured for 24 h in the presence or absence of dexamethasone (microM). Only the mRNA from normal hepatocytes cultured for 24 h in the absence of any glucocorticoid was obviously positive for IL-6. The increased expression of gamma-fibrinogen mRNA indicated the presence of inflammation. These results confirm the identification of IL-6 as an exogenous hormone for regulating normal hepatic acute phase protein synthesis in inflammation and rules out an autocrine mechanism being active in the liver in normal homeostasis. |
| Databáze: | OpenAIRE |
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